Income Taxes - Components of Low Income Housing Investment (Details) - USD ($)	3 Months Ended	9 Months Ended
Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Income Taxes
Low income housing tax credits	$ 141,000	$ 180,000	$ 422,000	$ 540,000
Low income housing investment expense	$ 148,000	$ 186,000	$ 445,000	$ 557,000

Represents information pertaining to investment expense on income tax housing investment.

No definition available.

Name:	htbk_EstimatedInvestmentGainLossOnIncomeTaxHousingInvestments
Namespace Prefix:	htbk_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration